Communications device for non-contact semiconductor memories

ABSTRACT

A low cost communications device (remote memory interface) highly adaptable to design changes. A data processing means encodes transmit data and decodes received data by software processing. A data processing means can be contrived for example with a general-purpose microcomputer, to decoded received data encode transmit data by software processing so that designing and mounting a dedicated IC is not necessary and a more compact communications device can be manufactured at a lower cost. The encode/decode method and other communications specifications can also be easily changed by modifying the software.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a communications device such asfor tape cassettes utilized in applications such as data storage andrelates in particular to a communications device ideal for mounting indevices for recording media containing internal non-conductive typesemiconductor memories.

[0003] 2. Description of Related Art

[0004] Devices called tape streamer drives are known in the related artas drive devices capable of recording and playback of digital data onmagnetic tape. Though also dependent on the tape length in the tapecassette constituting the medium, the tape has a huge recording capacityfrom several hundred to several thousand gigabytes. These tape streamerdrives are therefore widely utilized in applications such as backing upthe data recorded on media such as the hard disk of the computer. Tapestreamer drives are also ideal for use in storing image data which has ahuge data size.

[0005] Tape streamer drives as described above have been proposed asrecording medium such as 8 millimeter VTR tape cassettes for recordingand playback with rotary heads utilizing the helical scan method.

[0006] However, since the only medium in these kind of magnetic tapecassettes was the tape medium, data such as control data or systemsetting data (all types of data other than the main data for storage)was also recorded on the tape.

[0007] However, on many occasions during actual operation, the data onthe tape cassette is preferably read while the tape cassette is in anunloaded state.

[0008] In devices for example such as library devices (changer devices)such as for storing a large number of tape cassettes in a magazineformat and selectively supplying these tape cassettes to a tape streamerdrive, the data is preferably read out by some means from the outer caseof the cassette to identify a cassette that must be shipped, etc.

[0009] Methods were therefore conceived for identifying information(such as the number of the cassette) by affixing a barcode label forexample to the cassette case and utilizing a library device to opticallyread out (scan) the barcode label to recognize the information.

[0010] The barcode method however was incapable of rewriting informationand the information quantity was small so that the barcode method wasinadequate for relatively sophisticated processing systems.

[0011] Tape cassettes incorporating nonvolatile memories within thecassette were developed for the above mentioned tape streamer systems.

[0012] These cassettes recorded information such as control informationfor data record/playback of the magnetic tape, and cassette usagehistory information and production information on the nonvolatilememory. Operation efficiency was greatly improved with this methodcompared to recording information such as control information on themagnetic tape.

[0013] More specifically, it was necessary to read and check informationsuch as this control information each time it was recorded or playedback on the magnetic tape and to rewrite it after recording or playback.When the control information for example was recorded at a designatedposition (for example, tape stop) on the magnetic tape, the tape had tobe driven to this designated position before and after each record andplayback operation. Furthermore, positions on the tape also had to bespecified for performing operations such as tape loading and unloading.However if nonvolatile memories were used for recording information suchas control information, then the above tasks were unnecessary.

[0014] Tape streamer drives were installed with connectors for accessingthese nonvolatile memories.

[0015] In recent years, along with nonvolatile memories, antennas andcommunication devices installed inside the tape cassette, are beingdeveloped for achieving access in a non-contact state with thenonvolatile memory. In other words, by installing wireless communicationtype circuits in tape streamer drives, data can be recorded and playedback on nonvolatile memories.

[0016] A tape cassette having a nonvolatile memory for this kind ofnon-contact wireless interface could be utilized for example reading outbarcode data from the nonvolatile memory.

[0017] For example, when one wants to select a particular tape cassettefrom among many tape cassettes stored in the magazine of a librarydevice, just reading out (scanning) the identification data on eachcassette by wireless communication is sufficient to select that tapecassette.

[0018] The communications section comprising the interface for this typeof non-contact memory however, incorporates an RF circuit (analogcircuit) for transmitting and receiving data (modulation signals) by wayof the antenna, and a digital circuit for encoding and decoding thetransmitted and received data.

[0019] Custom (dedicated) IC circuits comprising this digital circuitfor encoding and decoding the transmitted and received data weredesigned and installed.

[0020] However, the utilizing of this custom IC increases thedevelopment period and the costs and prevents manufacturing a compactand low-cost communications device. This custom IC must also beredesigned every time changes are made such as in the communicationsspeed or the signal modulation (encoding/decoding) method also causing alonger device development period and higher development costs.

SUMMARY OF THE INVENTION

[0021] In view of the above circumstances of the related art, thepresent invention is a communications (interface) device attached to arecording medium for sending and receiving data to a non-contactsemiconductor memory having a memory section to store informationrelating to that recording medium, and a communications section forsending and receiving data to the storage section without making directcontact, in which the device comprises a sending/receiving means forsending and receiving by non-contact communication, and a dataprocessing means for encoding transmit data and decoding receive data.The data processing means is comprised by a microcomputer, and alongwith encoding and decoding by software processing utilizing a memorysection connected to or incorporated into this microcomputer, the clockfrequency is a frequency matching the carrier frequency of thetransmit/receive signal of this sending/receive means.

[0022] The above structure is further comprised of a clock generatormeans, and the clock and transmit/receive signal carrier of the dataprocessing means are generated from the clock generator means based onthe clock frequency.

[0023] The data processing means accumulates into the memory section thereceived data obtained from the sending/receiving means at specifiedperiods, and decodes the received data that was accumulated in thememory section.

[0024] The data processing means encodes the transmit data in the memorysection, and supplies a data stream of that transmit data to thesending/receiving means for transmission.

[0025] In other words, in the present invention, the data processingmeans encodes the transmit data and decodes the receive data by softwareprocessing. The data processing means is for example comprised by ageneral-purpose microcomputer and therefore is flexible versus changesin the design and specifications.

[0026] The clock frequency corresponds to the carrier of thetransmit/receive signal so that synchronized processing is easy, and thedevice structure and software processing are simplified.

[0027] As can be seen by the foregoing description of the presentinvention, the data processing means encodes transmit data and decodesreceive data by software processing. In other words, a data processingmeans comprised by a general-purpose microcomputer, encodes the transmitdata and decodes the receive data by software processing so that acustom (dedicated) ID does not have to be designed and installed, thusrendering the effect that a lower-cost and more compact communicationsdevice can be achieved. Also, changes such as in the communicationsspeed or the signal modulation (encoding/decoding) method can be handledby making software changes which also contributes to lowering the costand shortening the communications device design time.

[0028] The clock frequency corresponds to the frequency of thetransmit/receive signal carrier so that synchronized processing is easy,and the device structure and software processing are simplified.

[0029] The processing by the data processing means further utilizes theinternal memory of the microcomputer or a connected memory as the memorysection. The receive data for example is accumulated in the memorysection, and the receive data accumulated in the memory section as datapackets are decoded. Encoding is also performed on the data fortransmission in the memory section that is configured as data packets,and a data stream of the applicable data packet is supplied to thesending/receiving means and transmitted. Checking of receive data andprocedures for generating transmit data can be flexibly achieved bythese kind of procedures.

BRIEF DESCRIPTION OF THE DRAWINGS

[0030]FIG. 1 is a descriptive view showing the overall internalstructure of the tape cassette utilized in the embodiment of theinvention.

[0031]FIG. 2 is a perspective view showing an external view of the tapecassette of the embodiment.

[0032]FIG. 3 is a descriptive circuit diagram showing the communicationmethod and the structure of the remote memory chip of the embodiment.

[0033]FIG. 4 is a descriptive view of the electromagnetic induction ofthe communication method of the embodiment.

[0034]FIGS. 5A and 5B are descriptive views (waveforms) showing themethod for modulating the transmission data of the embodiment.

[0035]FIGS. 6A to 6D are descriptive views (waveforms) showing of thetransmit/receive data of the embodiment.

[0036]FIG. 7 is a descriptive view of the transmit/receive datastructure of the embodiment.

[0037]FIGS. 8A and 8B are descriptive views (diagrams) of the Manchesterencoding of the embodiment.

[0038]FIG. 9 is a table showing the contents of the remote memory chipof the embodiment.

[0039]FIG. 10 is a block diagram of the tape streamer drive of theembodiment.

[0040]FIG. 11 is a descriptive view of the structure of the librarydevice of the embodiment.

[0041]FIG. 12 is a descriptive view of the outer case structure of thelibrary device of the embodiment.

[0042]FIG. 13 is a descriptive view of the magazine of the librarydevice of the embodiment.

[0043]FIG. 14 is a descriptive view of the hand unit of the librarydevice of the embodiment.

[0044]FIG. 15 is a descriptive view of the hand unit of the librarydevice of the embodiment.

[0045]FIG. 16 is a descriptive view of the hand unit of the librarydevice of the embodiment.

[0046]FIG. 17 is a block diagram of the library device of theembodiment.

[0047]FIG. 18 is a block diagram of the structure of the remote memoryinterface of the embodiment.

[0048]FIG. 19 is a flow chart of the transmit processing of theembodiment.

[0049]FIG. 20 is a flow chart of the receive processing of theembodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0050] The embodiments of the present invention are described next.

[0051] The example in this embodiment utilizes a data storage systemcomprised of a tape cassette installed with a nonvolatile memory, a tapedrive device (tape streamer drive) capable of recording and playback ofdigital data for this tape cassette with memory, a library devicecapable of selectively storing many tape cassettes and loading them inthe tape streamer drive, as well as a host computer, etc.

[0052] The tape streamer drive and library device read and writeinformation by wireless data communication with the nonvolatile memory(remote memory chip) installed within the cassette. The exampleapplicable to the present invention, is a communications device (remotememory interface) for wireless data communication with a remote memorychip installed in a library device.

[0053] The description is given in the following steps.

[0054] 1. Tape cassette structure

[0055] 2. Remote memory chip structure, communications method, andrecorded data

[0056] 3. Tape streamer drive structure

[0057] 4. Library device structure

[0058] 5. Remote memory interface structure and operation

[0059] 1. Tape Cassette Structure

[0060] The tape cassette for the tape streamer drive and library deviceis described while referring to the FIG. 1 and FIG. 2.

[0061]FIG. 1 shows an overall view of the internal structure of a tapecassette 1. A reel 2 a and 2 b are installed inside the tape cassette 1as shown in this figure. A magnetic tape 3 with a tape width of eightmillimeters is wound between the reel 2 a and the reel 2 b.

[0062] A remote memory chip 4 incorporating a nonvolatile memory and acontrol circuit for the memory is installed in this tape cassette 1.This remote memory chip 4 is contrived to be able to perform datatransfer by communication utilizing electromagnetic induction with theremote memory interfaces 30 and 32 with the tape streamer drive 10 andlibrary device 50 described later on, and therefore is installed with anantenna 5.

[0063] Though described in detail later on, information such asproduction information and serial numbers, tape thickness and length,material, information relating to the usage history of data recorded foreach partition and user information are stored on the remote memory chip4.

[0064] In these specifications, information of various types stored onthe remote memory chip 4 is mainly utilized for control of recording andplayback of the magnetic tape 3 so this information is referred tocollectively as “control information”.

[0065] By installing a nonvolatile memory within the tape cassette caseand storing controlling information inside that nonvolatile memory inthis way, and by providing an interface to read and write on thatnonvolatile memory in the tape cassette of the tape streamer drive, thecontrol information involving the recording and playback of data onmagnetic tape can be read out and written on the nonvolatile memory, sothat recording and playback on the magnetic tape 3 can be efficientlyperformed.

[0066] The magnetic tape for instance, does not have to be completelyrewound when loading or unloading the tape, in other words, loading andunloading can be done from any position along the tape. The controlinformation on the nonvolatile memory can be rewritten in data editing,etc. Furthermore, many partitions can be established on the tape toallow easy control when needed.

[0067] An external view of the tape cassette 1 is shown in FIG. 2. Theoverall case is comprised of a top case 6 a, a lower case 6 b and aguard panel 8. The structure is basically the same as the tape cassetteused in an ordinary 8 millimeter VTR.

[0068] A terminal 6 c is installed on the label surface 9 on the side ofthe tape cassette 1, and is an electrode terminal for a tape cassettehaving an internal contact type memory not described in this embodiment,and therefore not used in the type incorporating the non-contact remotememory chip 4 in this embodiment. It is provided here only to maintainthe compatibility of the tape cassette shape in the device.

[0069] A cavity 7 is formed on both sides of the case to allow grippingthe tape cassette when for example being conveyed by the library device50 described later on.

[0070] 2. Remote Memory Chip Structure, Communications Method, andRecorded Data

[0071]FIG. 3 shows the structure of the remote memory interface 30 (32)installed in the tape streamer drive and library device forcommunication between the remote memory chip 4 and the remote memorychip 4. A concept type block diagram is used in this figure toillustrate the communication method for the remote memory interface 30(32). A detailed structure of the remote memory interface 32 of thisembodiment is described later on in FIG. 18.

[0072] The remote memory chip 4 constituted by a semiconductor IC asshown in FIG. 3 contains a regulator 4 a, RF section 4 b, logic section4 c, and an EEP-ROM 4 d. A remote memory chip 4 of this kind is mountedon a printed circuit board clamped inside a tape cassette 1, and anantenna 5 formed on the copper foil portion of the printed circuitboard.

[0073] This remote memory chip 4 is configured to receive electricalpower in a non-contact method supplied from an external section. A 13.56MHz carrier wave for example is utilized for example for communicationsbetween the tape streamer drive 10 and the library device 50 relatedlater on, and the regulator 4 a converts this 13.56 MHz carrier wave todirect current power by receiving an electromagnetic field with theantenna 5 from the tape streamer drive 10 and the library device 50.This direct current power is supplied as the operating power source forthe RF section 4 b and the logic section 4 c.

[0074] In the RF section 4 b, a diode D1, resistors R1, R2, condensersC1, C2 and switching element Q1 are connected for example, as shown inthe figure, and along with supplying the received information (inductivevoltage) to the logic section 4 c, a switching control voltage V4 fromthe logic section 4 c modulates the information for transmitting.

[0075] The logic section 4 c controls processes such as the read andwrite processing on for example the EEP-ROM 4 d according to the decodedinformation (commands) and decoded receive signals from the RF section 4b.

[0076] The remote memory interfaces 30 and 32 on the other hand,modulate the 13.56 MHz carrier wave by means of transmit data in amodulator 100M, and transmit it (the modulated carrier) from the antenna31 to the remote memory chip 4. The information sent from the remotememory chip 4 is demodulated by a demodulator 100D and the dataobtained.

[0077] Communication between the remote memory chip 4 and the remotememory interfaces 30 and 32 is described next.

[0078] The communication between the remote memory chip 4 and the remotememory interfaces 30 and 32 is basically performed based on theprinciple of electromagnetic induction.

[0079] An antenna 31 (33) connected to the remote memory interfaces 30,32 as shown in FIG. 4, is formed as a loop coil Lrw. A magnetic field isgenerated on the periphery of the loop coil Lrw by making an electricalcurrent Irw flow in this antenna 31 (33).

[0080] An antenna 5 on the other hand connected to the remote memorychip 4 is formed by a loop coil Ltag, and an electromagnetic voltagefrom a magnetic filed emitted from the loop coil Lrw, is generated inthe end of the loop coil Ltag, and this is input to the IC constitutingthe remote memory chip 4.

[0081] The extent of coupling of the antenna 31 and the antenna 5changes according to their positional relationship, so an M-coupledtransformer is provided, and a model is therefore shown as in FIG. 3.

[0082] Though not shown in FIG. 3, a resonant condenser may be connectedto the antennas 5, 31 to extend the communication distance. When thecommunication distance is long and the magnetic field coupling the loopcoil Lrw and loop coil Ltag becomes small, adding this condenser canincrease the resonance. In other words, the voltage generated in theloop coil Ltag increases due to resonance, so that the communicationdistance which is limited by the power required by the remote memorychip 4 can be extended. The impedance of the resonant circuit increasesso that during transmission the amplitude modulation fluctuations of theloop coil Lrw are transmitted more efficiently than the loop coil Ltag.During receive, the impedance fluctuations (described later on) of theremote memory chip 4 are transmitted more efficiently.

[0083] The magnetic field emitted by the antennas 31 (33) and theinductive voltage of the remote memory chip 4 are varied according tothe electrical current flowing in the antennas 31 (33). The modulator100M in the remote memory interfaces 30, 32 therefore modulates thecurrent of the antennas 31 (33), so that data can be transmitted to theremote memory chip 4. The remote memory interfaces 30, 32 in other wordsmodulate the magnetic field with transmit data, and the remote memorychip 4 demodulates the components by using the diode D1 and condenser C2of the inductive voltage that was input, or in other words demodulatethe data from the alternating current component V2 appearing afterrectification.

[0084] When sending data back to the remote memory interfaces 30 and 32the remote memory chip 4 varies the input impedance according thattransmit data. An oscillator is therefore not installed for sending datato the remote memory chip 4.

[0085] The logic section 4 c in other words, supplies the transmit dataV4 to the gate of the switching element Q1 to drive the switchingelement Q1. The effect of the resistor R2 on the input impedance isturned on and off in this way, and the input impedance varies.

[0086] When the impedance as seen from the antenna 5 of remote memorychip 4 changes, the impedance of the M-coupled antennas 31 (32) alsochanges, and a fluctuation in this way appears in the electrical currentIrw and voltage Vrw across the terminals of the antenna 31 (33). Thevariable (fluctuating) component is demodulated in the demodulator 100Dof the remote memory interfaces 30, 32, and data can be received fromthe remote memory chip 4.

[0087] The remote memory chip 4 itself possesses no battery, and afterdetecting the induction voltage caused in the antenna 5, the regulator 4a as described above, obtains a current and voltage from the directcurrent components of the voltage V1.

[0088] The induction voltage V0 is affected by the variations(fluctuations) occurring due to the functioning of the remote memorychip 4 and also due the transmit/receive data, so that the voltage mustbe stabilized with the regulator 4 a in order to achieve stableoperation of the remote memory chip 4.

[0089] Therefore, when the remote memory interfaces 30, 32 arecommunicating with the remote memory chip 4, the remote memory chip 4 isset to power-on by first outputting a carrier wave from the antennas 31(33). That power-on condition is then maintained until completion of aseries of communication access (write and read) During transmit ofcommand for read and write, the remote memory interfaces 30, 32 performASK (amplitude shift keying) modulation and send command data to theremote memory chip 4. When the remote memory interfaces 30, 32 receivean acknowledgment from the remote memory chip 4 for these transmitcommands, ASK demodulation of the carrier wave is performed and thereceive data obtained.

[0090] In the period of repeated access with the remote memory chip 4,the remote memory interfaces 30, 32 continue to output a carrier wave,so the remote memory chip 4 is maintained at power-on.

[0091] The data clock required for communication in the remote memorychip 4 is obtained by frequency division of the 13.56 MHz carrierfrequency of the remote memory interface 30, 32 and generating it in thelogic section 4.

[0092] The signal sent to the remote memory chip 4 from the remotememory interfaces 30, 32 is ASK modulated by transmit data on the 13.56MHz carrier frequency.

[0093] The ASK demodulation signal is shown in FIG. 5A and FIG. 5B.Transmit data Vs such as in FIG. 5A, modulates the carrier A0, and anASK modulation signal V3 as shown in FIG. 5B is obtained. This ASKmodulated wave V3 is expressed by V3=A0(1+k*Vs (t)).

[0094] The ASK modulation rate is for example 15 percent.

[0095] The remote memory chip 4 send and receive signals are shown inFIG. 6A through FIG. 6D.

[0096] This ASK (amplitude shift keying) modulated wave V3 generated inthe remote memory interfaces 30, 32, appears as an inductive voltage V0in the antenna 5 of remote memory chip 4. The carrier wave that wasenvelope-detected by the detector circuit (diode D1), is obtained as adetector output V1 as in FIG. 6A. Besides transmit data from the remotememory interfaces 30, 32, this detector output V1 also contains datatransmitted by the remote memory chip 4 itself.

[0097] The DC component is then eliminated by the condenser C2, and thedemodulated data V2 such as in FIG. 6B is input to the logic section 4c.

[0098] The logic sum of the demodulated data V2 and receive window t1are obtained in the logic section 4 c, and the actual receive data V2′is restored as shown in FIG. 6C. The transmit data is in this wayobtained on the remote memory chip 4 side from the remote memoryinterfaces 30, 32.

[0099] The remote memory chip 4 that received the data, sends therequired data to the remote memory interfaces 30, 32 after processing ofthe data from periods t1 through t2. Transmit data V4 for example isshown in FIG. 6D, and the switching element Q1 is turned on and off bythis transmit data V4 so that the impedance is varied as describedabove, and the data is in this way sent to the remote memory interfaces30, 32.

[0100] The impedance (fluctuation) variation rate in this case is forexample 50 percent or more.

[0101] On the remote interface 30, 32 side, the impedance variation atthe remote memory chip 4 causes variations (fluctuations) in theelectrical current Irw and voltage Vrw in the antennas 31 (33) coupledby M-coupling so that upon detection of this variation (fluctuation),the transmitted data is demodulated by the demodulator 100D.

[0102] The modulated wave V3 is expressed as V3=A0*(1+m*V4 (t)) at thistime. The extent of M-coupling is greatly dependent on the distancebetween remote memory chip 4 and the remote memory interface 30, 32 sothat obtaining a large impedance on the remote memory chip 4 side isimportant.

[0103] A detector output is obtained in the same way as FIG. 6A even onthe remote memory interface 30, 32 side, and by binarizing the signal ofFIG. 6B, receive data such as in FIG. 6C is obtained.

[0104] The above described the sending and receiving of data between theremote memory interface 30, 32 and the remote memory chip 4.

[0105] The sent and received data has a structure as shown in FIG. 7. Inother words, a 2-byte preamble, a 3-byte synch, a 1-byte length, 4 or 20bytes of data, and a 2-byte CRC (cyclic redundancy check).

[0106] The preamble is added with the objective of synchronizing thetransmitted data with a clock pulse. A synch is then added afterpreamble, as a start position check and a logic check. The length isthen added to indicate the data length. Following the data, a CRC isadded having error detection and error correction capability.

[0107] The data for sending and receiving between the remote memoryinterfaces 30, 32 and the remote memory chip 4 is data subjected toso-called Manchester encoding.

[0108] Manchester encoding is a type of BPSK (binarypulse shift keying)modulation and data of “0” is sent as “01”; and data of “1” is sent as“10”. The DC components are therefore treated so as not to ride thesignal.

[0109] The coding clock pulse divides the 13.56 MHz carrier wave by 64for use at approximately 212 KHz. The bit rate of the transmit/receivedata is therefore equivalent to 106 Kbps.

[0110] An example of Manchester encoding is shown in FIG. 8A.

[0111] Here, if the data string for transmitting is “101100”, then “01”or “10” is encoded with the binary clock, so the data becomes,“100110100101”. Even if the data has successive “0”s or “1”s, the ASK(amplitude shift keying) modulates the carrier with a “01”or “10” sothat the DC component does not ride the signal.

[0112] During modulation of the carrier wave, a “01” is a “large/small”amplitude, and a “10” is a “small/large” amplitude.

[0113]FIG. 9 next shows an example of control information contentsstored on the EEP-ROM 4 d of remote memory chip 4. The numerals (1)through (32) in the figure are used only for the purpose of conveniencein the description and do not correspond to the data position formatwithin this EEP-ROM 4 d. The contents shown in this list are an example,and in some cases, contents not shown in the example may also be stored.

[0114] Each item in the contents is briefly explained.

[0115] (1) Memory Format

[0116] This content item shows the type of format for the memoryinstalled within the tape cassette 1 such as a contact type ornon-contact type format. In this example, a numeral showing thenon-contact type is stored in the remote memory chip 4.

[0117] (2) Control Flag

[0118] This content item lists the type of status during shipment fromthe factory.

[0119] (3) Manufacturer's Identifier (1 byte)

[0120] This content item lists the code number of the manufacture ofthis cassette tape 1. A one byte code value is set for example accordingto the manufacturer and stored.

[0121] (4) Secondary Identifier

[0122] This content item lists the attribute information of the tape orin other words, is the type information for the tape cassette 1. A onebyte code value is set respectively according to the type of tapecassette 1, and the applicable code value is stored.

[0123] (5) Serial No. (32 Bytes)

[0124] This content item lists the particular number comprised of 32characters (32 bytes) stored in the remote memory chip. A unique (orcharacteristic) code is respectively assigned to each tape cassette 1.

[0125] (6) Serial No. of CRC Code (2 Bytes)

[0126] This content item lists the two-byte CRC for the above mentioned32 byte serial number.

[0127] The total 36 bytes of information constituting the manufacturer'sidentifier, secondary identifier, serial number and CRC code for theserial number in the content items (3) through (6), are particularinformation for each tape cassette as data listed during shipment. Thisinformation is utilized for example in certifying the cassette.

[0128] (7) Memory Production Yr. Mo. Dy.

[0129] (8) Memory Production Line Name

[0130] (9) Memory Production Plant Name

[0131] (10) Memory Production Manufacturer's Name

[0132] (11) Memory Model Name

[0133] (12) Cassette Production Line Name

[0134] (13) Cassette Production Yr. Mo. Dy.

[0135] (14) Cassette Production Plant Name

[0136] (15) Cassette Production Manufacturer's Name

[0137] (16) Cassette Name

[0138] Data equivalent to each of the above respective content items islisted.

[0139] (17) OEM Customer Name

[0140] This content item lists the OEM customer name but when destinedfor general use is listed as “GENERIC”.

[0141] (18) Tape Characteristic Specifications Information

[0142] This content item lists information such as magneticcharacteristics, electrical characteristics, length and tape thicknessof the magnetic tape 3.

[0143] (19) Maximum Communication Speed

[0144] This content item lists the information transfer rate of thememory.

[0145] (20) Block Size

[0146] This content item lists the memory block size such as “16 bytes”.

[0147] (21) Memory Capacity

[0148] This content item lists the memory capacity such as “8KByte”.

[0149] (22) Read-out Dedicated Area Start Address

[0150] For example, 0000h.

[0151] (23) Read-out Dedicated Area End Address

[0152] For example, 00FFh.

[0153] (24) Various Pointers

[0154] The pointer to each data type on the memory, forming the routefor the list structure data type.

[0155] (25) Memory Control Information

[0156] Content item listing control information relating to the memory.

[0157] (26) Volume Attribute

[0158] Content item listing information such as the read-prohibit,write-prohibit on the magnetic tape 3 during intermittent processing.

[0159] (27) Volume Information

[0160] Content item listing information relating to the volume historysuch as the initialization count and number of partitions on themagnetic tape 3.

[0161] (28) Volume Usage History Information

[0162] Content item listing information for overall usage of thecassette by calculating the usage history of each partition on themagnetic tape 3. This includes not only the loading count for the tape,but also characteristic information involving the volume such as theloading count for the cassette.

[0163] (29) High-speed Search Assist Map Information

[0164] Content item listing data map information necessary forimplementing a high speed search function to make maximum use of reelmotor performance without obtaining ID information in real-time from themagnetic tape 3.

[0165] The operation of this high speed search function is as follows.In a process for recording data on the magnetic tape 3, the logicposition information is written on a high-speed search support map ateach 10 meters of tape drive. When then searching for the file positionon the magnetic tape 3, this map is first checked, and the nearestposition further having a sufficient tape margin before the next 10meter position is selected. The tape thickness and reel diameter isalready known so that by calculating the reel FG pulses up to thecalculated position, the tape can be fed without having to read the tapeID at all. In other words, the tape can be driven at high speed withouthaving to read out the ID from the magnetic tape. Upon reaching thecalculated position during this kind of high-speed tape drive, the tapethen slows to a speed where the ID data can be read out from themagnetic tape 3, and a normal high-speed search is made for the finalfile position specified by the host computer.

[0166] (30) Unload Position Information

[0167] Multiple partitions appended with numbers in order, from thebeginning of the magnetic tape can be efficiently monitored by using thememory (remote memory map).

[0168] Multiple partition specifications allow loading and unloading ateach partition (unit) however to unload at a particular partition, acheck must be made to find whether the tape was loaded again at theprevious unloading position.

[0169] So in such cases, the unloading position must be stored in thememory. This assures that even if mistakenly loaded at another locationthat the mistake will be detected, and prevents unexpected writing on anunscheduled position or readout at an unscheduled position.

[0170] (31) User Free Area

[0171] The user free area is a memory area freely writable by the uservia a serial Interface and a host interface (SCSI) over the Internet.The serial interface is contained in the drive device, and is utilizableby the library controller and for maintenance.

[0172] (32) Reserved Area

[0173] An empty area of the memory available for use during futureexpansion.

[0174] 3. Tape Streamer Drive Structure

[0175] The tape streamer system of this embodiment is comprised of atape streamer drive 10 for recording and playback of a magnetic tape 3of the tape cassette 1, a library device 50 capable of storing many tapecassettes 1 and selectively loading them in the tape streamer drive 10,and also a host computer for controlling the (device) operation. Thelibrary device 50 and the tape streamer drive 10 are capable ofcommunicating with the remote memory chip 4 of tape cassette 1.

[0176] The structure of the tape streamer drive 10 is first explainedhere while referring to FIG. 10. This tape streamer drive 10 records andplays back the magnetic tape 3 of tape cassette 1 by the helical scanmethod.

[0177] Two recording heads 12A, 12B and three playback heads 13A, 13Band 13C are for example, installed in the rotating drum 11 of the tapestreamer drive 10 as shown in FIG. 10.

[0178] The recording heads 12A, 12B have a structure with two gaps ofmutually different azimuth angles installed in extremely closeproximity.

[0179] The playback heads 13A, 13B and (13C) are heads (13A and 13C havethe same azimuth) with mutually different azimuth angles, and forexample are installed 90 degrees apart from each other. This is for alsoutilizing the playback heads 13A, 13B and 13C for readout (so-calledread-after-write) immediately after recording.

[0180] Along with being rotated by the drum motor 14A, the rotating drum11 also winds up the magnetic tape 3 that was pulled out. The magnetictape 3 is also conveyed by the capstan motor 14B and a pinch roller notshown in the drawing. The magnetic tape 3 is also wound on the reels 2A,2B. These reels 2A and 2B are rotated respectively in the forwarddirection or the reverse direction by the respective reel motors 14C and14D.

[0181] The drum motor 14A, capstan motor 14B and reel motors 14C, 14Dare respectively driven by electrical power applied from the mechanicaldriver 17. The mechanical driver 17 drives each motor based on controlfrom the servo controller 16. The servo-controller 16 controls therotation speed of each motor, to drive the tape during normalrecord/playback and high-speed recording, and to drive the tape duringfast forward and rewind, etc.

[0182] The constants utilized in servo-control of each motor by theservo-controller 16 are stored in the EEP-ROM 18.

[0183] The servo-controller 16 connects bi-directionally, by way of theinterface controller/ECC formatter 22 (hereafter called, IF/ECCcontroller) with the system controller 15 for overall system control.

[0184] An SCSI interface 20 is utilized in the tape streamer drive 10for input and output of data. During recording of data for example, datais successively input from the host computer via the SCSI interface inunits of transfer data called fixed length records, and supplied to acompression/expander circuit 21. In a tape streamer drive system of thistype, a mode is also used for transferring data from the host computer40 in collective units of variable length data.

[0185] The compression/expander circuit 21 if necessary, can compressthe input data by means of a specified method. If for example, LZ codingis utilized as the compression method, a dedicated code assigned forcharacter strings processed previously by this method is stored in adictionary format. Character strings input from hereon are compared withthe dictionary contents, and if the character strings of the input datamatch the dictionary code, then the character string data is substitutedwith dictionary code. Input character string data that did not match thedictionary is successively stored in dictionaries allotted with a newcode. Data compression is performed in this way, by storing(registering) input character string data in the dictionary and,substituting the character string data with the dictionary code.

[0186] The output of the compression/expander circuit 21 is supplied tothe IF/ECC controller 22. The IF/ECC controller 22 however, temporarilystores the output from the compression/expander circuit 21 in a buffermemory 23. Due to control implemented by the IF/ECC controller 22, thedata accumulated in this buffer memory 23 is ultimately treated as fixedlength data equivalent to a 40 track portion of magnetic tape called agroup. The tape is then subjected to ECC formatting.

[0187] In the ECC formatting, along with adding an error correction codeto the recorded data, the data is also modulated to adapt it to magneticrecording and then supplied to an RF processor 19.

[0188] The record data supplied to the RF processor 19 is amplified,subjected to record equalization, a recording signal generated and thensupplied to the recording heads 12A, 12B. Data is in this way recordedon the magnetic tape 3 by the recording heads 12A, 12B.

[0189] In a brief description of data playback operation, the recordingdata on the magnetic tape 3 is read out as an RF playback signal fromthe playback heads 13A, 13B, and processing such as playback equalizing,playback clock generation, sampling and decoding (such as Viterbidecoding) are performed on that playback output by the RF processor 19.

[0190] The signal readout in this way, is supplied to the IF/ECCcontroller 22 and error correction first performed. After next beingstored in the memory buffer 23, it is read out at a specified time pointand supplied to the compression/expander circuit 21.

[0191] The compression/expander circuit 21 expands the data ifdetermined by the system controller 15, that the data was compressed bythe compression/expander circuit 21 during recording. If the data is notcompressed then the data is passed through to the output withoutexpanding the data.

[0192] The data output from the compression/expander circuit 21 isoutput by way of the SCSI interface 20 to the host computer 40 asplayback data.

[0193] The remote memory chip 4 inside the tape cassette 1 is shown inthis figure. The tape cassette 1 body is loaded in the tape streamerdrive and the remote memory chip 4 is capable of inputting andoutputting data to the system controller 15 in a non-contact state byway of the remote memory interface 30.

[0194] The above described communication is performed with the remotememory chip 4 by way of the remote memory interface 30 and the antenna31. The system controller 15 can in this way access the remote memorychip 4 for reading and writing.

[0195] Data transmission with the remote memory chip 4 is performed byway of commands from the device and corresponding acknowledgments fromthe remote memory chips. However, when the system controller 15 issues acommand to the remote memory chip 4, that command data is encoded forthe remote memory interface 30 in the data structureof FIG. 7, andASK-modulated and sent as described above.

[0196] The transmitted data is received by the antenna 5 in the tapecassette 1 as described above, and the logic section 4 c operatesaccording to the contents designed in the received data (command). Thedata sent along with the write command is for example written into theEEP-ROM 4 d.

[0197] When a command is issued in this way from the remote memoryinterface 30, the remote memory chip 4 issues a correspondingacknowledgment. In other words, the logic section 4 c of the remotememory chip 4 modulates the data in the RF section 4 b as anacknowledgment, and transmits it from the antenna 5.

[0198] When an acknowledgment of this kind is received at the antenna31, that received signal is demodulated in the remote memory interface30, and supplied to the system controller 15. When a readout command forexample is issued to the remote memory chip 4 from the system controller15, the remote memory chip 4 transmits the readout data from the EEP-ROM4 d as well as a code to acknowledge that command. Whereupon, thereadout data and the code acknowledgment are received and demodulated inthe remote memory interface 30, and supplied to the system controller15.

[0199] By having this remote memory interface 30, the tape streamerdrive 10 can therefore access the remote memory chip 4 within the tapecassette 1.

[0200] In this kind of non-contact data exchange, the data is overlappedonto the carrier wave by ASK modulation, so that the original data isformed into packet data.

[0201] Packetizing in other words is performed, making data consistingof commands and acknowledgments into headers and parities, and addingother information required for a packet. Performing modulation afterpacket code conversion allows sending and receiving it as a stable RFsignal.

[0202] Data used in the various processing by the system controller 15is stored in an S-RAM 24 and a flash ROM 25.

[0203] Constants utilized for control (processes) are for example storedin the flash ROM 25.

[0204] The RAM 24 is utilized as a work memory, and as a memory forprocessing and storage of data such as data readout from the remotememory chip 4, write data in the remote memory chip 4, mode data in tapecassette units, and various types of flag data.

[0205] The S-RAM 24 and a flash ROM 25 may be made to comprise theinternal memory of the microcomputer that constitutes the systemcontroller 15, or may be utilized to comprise the work memory 24constituting a portion of the area of the buffer memory 23.

[0206] Information is mutually transmitted between the tape streamerdrive 10 and the host computer 40 as described above using the SCSIinterface 20. The host computer 40 however, uses SCSI commands tocommunicate with the system controller 15.

[0207] 4. Library Device Structure

[0208] The library device 50 is described next.

[0209]FIG. 12 is an external view of the outer box of the library device50. FIG. 11 shows the mechanism comprising the library device 50installed within the outer box.

[0210] The mechanism comprising the library device 50 is first describedin FIG. 11.

[0211] In the library device 50 as shown in the figure, on a control box53, four magazines 52 capable of storing about 15 tape cassettes 1, areattached for example, to a rotating carousel 51. The magazines 52 areselected by rotation of the carousel 51.

[0212] A hand unit 60 for storing and extracting the tape cassettes 1 inthe magazines 52, is capable of moving up and down (Z axis direction).In other words, a gear mechanism is formed along the Z axis 54. The handunit 60 is contrived so the axial bearing 62 engages with the gearmechanism, so that the Z axis 54 is rotated by the Z motor 73, and thehand unit 60 is moved up and down.

[0213] The hand unit 60 is installed so that the hand table 63 moves inthe Y direction versus the base 61. A pair of hands 64 are installed atthe ends of the hand table 63. This pair of hands 64 can grip andrelease the tape cassette 1 by opening and closing in the X direction.

[0214] A plurality of tape streamer drives 10 are installed beneath thecarousel 51. Each tape streamer drive 10 has the structure as describedabove in FIG. 10.

[0215] The hand unit can extract the tape cassette 1 from the desiredmagazine 51 on the carousel 51 by means of this mechanism, and canconvey it to the desired tape streamer drive 10. Conversely, the tapecassette 1 extracted from the tape streamer drive 10 can be stored inthe desired position of the desired magazine.

[0216] The external case box for housing this mechanism has a front door55 largely comprising the front surface, and a handle 58 for opening andclosing the front door 55. The front door 55 can also be locked by alock 59. A section on the front door 55 is installed with a transparentpanel 55 a, allowing a visual check of the interior to be made.

[0217] An operating panel 57 and a post 56 are formed above the frontdoor 55. The post 56 is formed to add or extract tape cassette 1 withthe front door 55 still closed. Though not shown in FIG. 11, the tapecassette 1 inserted from the post 56 can be conveyed to the desiredposition within the magazine 52 by the hand unit 60. The tape cassette 1conveyed by the hand unit 60, can also be extracted from the host 56.

[0218] The keys for operation by the user are installed on the operatingpanel 57. Information from operating the keys on the operating panel 57are input to the library controller 80 described later on, and operationis implemented by operation by the library controller 80. Operation bythe user on this operating panel 57 include commands for inserting andextracting the tape cassette 1 from the host 56, and adjusting thelibrary device 50, etc.

[0219] The structure of the magazine 52 is shown in FIG. 13.

[0220] Each magazine 50 is formed of approximately 15 storage sections52 a and one tape cassette 1 can be stored in each storage section 52 a.

[0221] A tape cassette 1 can easily be inserted in a storage section 52a and the size of the storage section 52 a can be set with sufficientgripping strength to prevent the tape cassette 1 from falling out attimes such as during rotation of the carousel 51. The tape cassette 1can also be easily extracted by the hand 64.

[0222] The height size a of each storage section 52 a is for example setto a=16 millimeters since the thickness of the tape cassette 1 isapproximately 15 millimeters.

[0223] The partition size b of the storage section 52 a is made as thinas possible to form many storage sections 52 a on the inside, and alsocalculated for a thickness with a certain amount of strength, so forexample b=3 millimeters.

[0224] The depth is set so that the back side of the tape cassette 1protrudes outward slightly when stored in the storage section 52 a. Inother words, FIG. 14 shows a tape cassette 1 inside the magazine 52 asseen from a flat view. The section d in the figure is the backside ofthe tape cassette 1 stored to protrude outwards. The section d at thistime is approximately 20 millimeters.

[0225] In this way, the tips of the hand 64 can easily grasp thecavities 7, 7 on both sides of the tape cassette 1.

[0226] The structure and operation of the hand unit 60 is described inFIG. 14, FIG. 15 and FIG. 16.

[0227]FIG. 14 shows the hand unit 60 in a matching position separatedfrom the tape cassette 1. FIG. 15 shows the hand unit 60 gripping thetape cassette 1. FIG. 16 shows the status in FIG. 15 as seen from theside.

[0228] The hand table 63 of hand unit 60 is installed to allow movementon the base 61. The hands 64, 64 are installed on the hand table 63.

[0229] In a status, where the axial bearing 62 installed in the base 61,is engaged with the Z axis 54, the entire hand unit 60 is gripped by theZ axis 54 so that the hand unit 60 moves up and down by the rotation ofthe Z axis 54, and at that point is positioned in a position facing thestorage section 52 a in the magazine 52, or the tape streamer drive 10.

[0230] The axial bearing 62 is formed at a position offset from themagazine 52 as seen from the direction of the front door 55 so that theZ axis 52 does not interfere when the front door 55 is opened and thetape cassette 1 is stored or extracted.

[0231] The hand table 63 is movable along a guide rail 8 in the base 61.In other words, the Y axis 71 having the gear mechanism, engages withthe hand table 63, and the Y axis 71 rotated forward or backward by a Ymotor 69, so that the hand table 63 moves in a direction towards or awayfrom the magazine 52.

[0232] A pair of hands 64, 64 are installed on the hand table 63, topivot on a support rod 67 used as a pivot point.

[0233] Each hand is set in a position pulled back by the plungers 65 onthe rear edge side, as well as a position pulled by the springs 66 nearthe front edge from the hand table 63. Therefore, in the period wherethe plungers 65 are off, both hands 64 are set to a closed position bythe force of the springs 66 as shown in FIG. 15. When the plungers 65are on and the hands are pulled back to a rearward position as shown bythe status of FIG. 14, so both hands 64 are in an open position opposingthe force of the springs 66.

[0234] In the operation to remove a tape cassette 1 from the magazine52, the Z axis 54 is first driven so that the hand unit 60 is moved to aposition at the (same) height as the storage section 52 a holding thedesired tape cassette 1.

[0235] Next, both hands 64, 64 are set to an open position by theplungers 65 as shown in FIG. 14, and in that state, the hand table 63 ismoved close to the magazine 52 by the Y motor 69.

[0236] When the hand table is moved to the status shown in FIG. 15, theplungers 65 are off at that point in time, and both hands 64 aretherefore moved to the closed direction by the force of the springs 66.The hands 64, 64 as shown in FIG. 15, are in a position gripping thetape cassette 1 on both sides (cavity 7).

[0237] The hand unit 64 is moved still in this state, by the Y motor 69in a direction away from the magazine 52 so that the tape cassette 1 isremoved.

[0238] The extracted tape cassette 1 is conveyed by the hand unit 60 tothe specified tape streamer drive 10, or post 56 or another storagesection 52 a of the magazine.

[0239] The reverse of the above operation is performed when the tapecassette 1 is stored inside the magazine 52.

[0240] A remote memory chip 4 however is mounted inside the tapecassette 1 as previously described, and the library device 50, the sameas the tape streamer drive 10, can access the remote memory chip 4.

[0241] The remote memory drive box 70 is installed in the hand table 63as shown in FIG. 14, FIG. 15, and FIG. 16, and the circuitry for theremote memory interface 32 is housed here. The structure of the remotememory interface 32 is described later on.

[0242] An antenna 33 is installed at a position facing the installationposition of the remote memory chip 4 on the rear side of the tapecassette 1.

[0243] In the state shown in FIG. 15 for example, the antenna 33 is inconsiderably close proximity to the remote memory chip 4 within the tapecassette 1. In this state, access can be achieved with the remote memorychip 4 by wireless communication.

[0244] In the state in FIG. 14, the antenna 33 and remote memory chip 4are (separated) at a distance e, however access can be achieved with ane distance of several centimeters.

[0245]FIG. 14, 15, and 16 show a barcode reader installed in the lowersection of the base 61.

[0246] By installing a barcode reader 72 for example, when a tapecassette 1 affixed with a barcode label is stored, the information onthat barcode label can be scanned (read). When installing the barcodereader 72, there are no particular restrictions on the installationpositions of the barcode reader 72 and the antenna 33. The barcodereader 72 for example, may be installed on the hand table.

[0247] The internal structure of the library device 50 having the abovemechanism is described next.

[0248] The library controller 80 is a section for controlling the entirelibrary device 50. The library controller 80 is capable of communicatingwith the tape streamer 10 and the host computer 40 by way of the SCSIinterface 87.

[0249] Therefore, the conveying of the tape cassette 1 between themagazine 52, the tape streamer drive 10 and the host 56, and the controlof the stored tape cassette 1 (for example, accessing the remote memorychip 4 within the tape cassette 1) is implemented by SCSI commands fromthe host computer 40.

[0250] The memory 81 comprises the work memory utilized in processing bythe library controller 80. Also, the operation information from theoperating panel 56 described above, is supplied to the librarycontroller 80, and the library controller 80 runs the required operationaccording to the panel operation.

[0251] A carousel controller 83 drives the rotation control motor 84according to instructions from the library controller 80, and makes thecarousel 51 rotate. In other words, runs the operation for selecting themagazine 52 with the hand unit 60. A carousel position sensor 85 detectsthe cursor 51 rotation position, or in other words, detects whichmagazine 52 (facing the hand unit 60) is selected. The carouselcontroller 83 makes the carousel 51 rotate while inputting informationfrom the carousel position sensor 83 so that the desired magazine 52 isselected.

[0252] A hand unit controller 82 drives the hand unit 60 based oninstructions from the library controller 80.

[0253] In other words, (hand unit controller 82) drives the Z motor 73to move the hand unit 60 along the Z axis. The Z axis position of thehand unit 60 is detected at this time by the hand position sensor 86 sothat the hand unit controller 82 drives the Z motor 73 while checkingthe position detection information from the hand position sensor 86. Thehand unit 60 can therefore be positioned at the specified heightposition as instructed by the library controller 80.

[0254] The hand unit controller 82 drives the Y motor 69 and the plunger65 at respective specified timings, and extracts and stores the tapecassette 1 with the hand 65 as described above.

[0255] Circuitry comprising the remote memory interface 32 is housed inthe remote memory driver box 70 installed within the above describedhand unit 60.

[0256] The structure of this remote memory interface 32 is describedlater on in FIG. 18 however the principle is the same as the remotememory interface inside the tape streamer drive 10 as described in FIG.10, having the structure shown in FIG. 3.

[0257] This remote memory interface 32 is connected to the librarycontroller 80.

[0258] This library controller 80 can by way of the remote interface 32,access and issue read and write commands to the remote memory chip 4inside the tape cassette 1 held by the tape cassette 1 or the hand unit60 in proximity to the antenna 33 inside the magazine 52.

[0259] In this case of course, access is also established for commandsfrom the library controller 80 and acknowledgments from the remotememory chip 4.

[0260] Though not shown in the drawing, when installing the abovedescribed barcode reader 72, besides installing a drive circuit for thebarcode reader 72, the scanned (read) information is supplied to thelibrary controller 80.

[0261] 5. Remote Memory Interface Structure and Operation

[0262] The structure and operation of the remote memory interface 32mounted in the library device 50 are described next.

[0263] The structure of the remote memory interface 32 is shown in FIG.18.

[0264] This remote memory interface 32 is comprised of a general-purposecomputer consisting of a CPU 10, an RF section 120, and a crystaloscillator consisting of a clock generator 130.

[0265] The RF section 120 is comprised of analog circuitry, andtransmits from the antenna 33, and receives data from the remote memorychip 4.

[0266] The processing for encoding the transmit data and for decodingthe receive data is performed by software control in the CPU 120.

[0267] An ASK/drive amp 124 is installed in the RF section 120 as thetransmit system, and during transmission supplies transmit data from theCPU 110.

[0268] Also, an envelope detector 121, an amp 122 and a comparator 123are installed as the receive system in the RF section 120.

[0269] The RAM 11 serving as the CPU 110 shown in the figure, is a RAMincorporated in a so-called microcomputer, and for example is 4kilobytes. In other words, a RAM commonly incorporated into ageneral-purpose microcomputer. A serial port 112 is also shown in thefigure. The internal RAM in the example is the RAM 111 however, needlessto say, a RAM may also be used as the external memory chip connected tothe CPU 110.

[0270] The CPU 110 complies with instructions such as commands from thelibrary controller 80 and achieves communication access with the remotememory chip 4. In other words, in response to the requests from thelibrary controller 80, performs processing such as encoding (generating)transmit data for the remote memory chip 4, and decoding of receive datafrom the remote memory chip 4, as well as processing to send theread-out data decoded from the remote memory chip 4 receive data, andacknowledgments to the library controller 80.

[0271] The operating clock for the CPU 110 is supplied from the clockgenerator 130. The clock generator 130 outputs for example, a 13.56 MHzclockpulse. The operating clock frequency of the CPU 110 is thereforeset at 13.56 MHz.

[0272] The carrier frequency for communications between the remotememory chip 4 and the remote memory interface is 13.56 MHz. Therefore,the 13.56 MHz clock from the clock generator 130 is utilized unchangedas the carrier frequency for the ASK/driver amp 124.

[0273] The 13.56 MHz clock from the clock generator 130 for the CPU 110,may for example be multiplied n times to obtain an operating clockfrequency of 13.56×n (MHz). In any case, the operating clock frequencyfor the CPU 110 in this example is generated from the clock frequencyfrom the clock generator 130. In other words, a frequency generated froma clock (fundamental) common to the carrier frequency may be used. Inthis example, a 13.56 MHz clock was output from the clock generator 130however, the operating clock frequency of the CPU 110 may be x times13.56 MHz or may be 1/x times the 13.56 MHz, and therefore dividers ormultipliers may be used in any combination. The division ormultiplication may also use non-integer values.

[0274] The transmit and receive operation for this kind of remote memoryinterface 32 is described next.

[0275] During transmit, or in other words when command packet data fortransmission has been supplied to the remote memory chip 4 from thelibrary controller 80, the CPU 110 places the preamble and synch at thefront of the data packet and the CRC at the rear. In other words,performs data encoding of the data structure shown in FIG. 7.

[0276] The transmit data is also Manchester-encoded as described in FIG.8A.

[0277] This Manchester-encoded transmit data having the data structureshown in FIG. 7 is stored in the RAM 111, and this stored transmit dataWD is output from the serial port 112 to the RF section 120 at atransmit speed twice 106 Kbps.

[0278] In the RF section 120, the 13.56 MHz carrier is modulated in theASK/drive amp 124, by ASK (amplitude shift keying) modulation withtransmit data WD as explained in FIG. 5A and FIG. 5B. The modulated waveis then sent from the antenna 33 to the remote memory chip 4.

[0279] During receive, the transmit data from the remote memory chip 4is output to the RF section 120 as information, by means of impedancevariations. Envelope detection as shown in FIG. 6A, is performed withthe modulation wave described in FIG. 5B by the envelope detector 121.Then, in the comparator 123, data as in FIG. 6B is binarized, to obtainthe received data as shown in FIG. 6C.

[0280] This received data RD is input to the CPU 110 from the serialport 112.

[0281] In the CPU 110, the stream of input received data is subjected to8× sampling at constant periods and accumulated in the RAM 111. Theseconstant periods may be fixed periods, for example 9.67 milliseconds issufficient. The amount required for accumulation in the RAM 111 is onekilobyte, and as described previously, four kilobytes of RAM in a CPU isgenerally sufficient.

[0282] An optimal sampling phase is determined from the receive dataaccumulated in the RAM 111, the preamble detected, synch detectionperformed, and the returned packet data is extracted from the remotememory chip 4. A CRC (cyclic redundancy check) check is also made.

[0283] The packet data from the remote memory chip 4 having undergonethis decoding is sent to the library controller 80.

[0284] The process implemented by CPU 110 software control in theoperation during the above sending and receiving is described in FIG. 19and FIG. 20.

[0285]FIG. 19 shows the sending process.

[0286] During the sending process, the CPU 110 forms transmit data WD inthe RAM 111. Therefore, in step F101, the preamble and synch comprisingthe transmit data are first of all written by Manchester encoding in theRAM 111.

[0287] Next, in step F102, the packet data to be transmitted, in otherwords, packet data such as commands sent from the library controller 80are Manchester-encoded in the same way, and written in the RAM 111.

[0288] The packet data sent between the CPU 110 and the librarycontroller 80 consist of a 1 byte length and 4 bytes or 20 bytes ofdata, as well as a 1 byte DCS (Data Check Sum). In this step F102, a 1byte length and 4 bytes or 20 bytes of data from among packet data sentfrom the library controller 80, are written in the RAM 11, with thelength and data in the send/receive data structure shown in FIG. 7.

[0289] When the library controller 80 requests data readout from theremote memory chip 4, the data is 4 bytes and when data writing isrequested the data is 20 bytes.

[0290] In other words, during data readout, the 4 bytes of data containsa read command and read block number (address).

[0291] During data write, of the 20 bytes of data, the write command andwrite block number (address) are shown with 4 bytes, and the remaining16 bytes are the actual data to be written.

[0292] In step F103, the CRC parity data of the packet (length and data)is calculated, the data Manchester-encoded in the same way, and writtenin the RAM 111.

[0293] In the process up to here, a packet of Manchester-encodedtransmit data WD, with the data structure of FIG. 7 is formed in the RAM111.

[0294] Next, in step F104, the transmit speed of the serial port 112 isset to twice the data transfer speed (106 Kbps).

[0295] Then, in step F105, the transmit data WD written in the RAM 111,is output to the serial port 112, supplied to the RF section 120 andtransmitted.

[0296] The receive process is shown in FIG. 20.

[0297] First of all, in step F201, the receive speed of the serial port112 is set to 8 times the data transfer speed (106 Kbps) during receive(receive period for acknowledgments of readout data after the transmitprocess for commands).

[0298] Then in step F202, the input from the serial port 112 is receivedat fixed intervals, and the receive data input from the RF section 120is accumulated in the RAM 111.

[0299] In this case, receive data RD supplied at 106 Kbps and consistingof a Manchester-encoded data string, is sampled at 8 times oversampling(848 KHZ) and input.

[0300] In this case for example, with receive data set for 8192sampling, the oversampling is 8 times, so is equivalent to receive dataRD of 1024 bytes. The fixed period for sampling in this case isequivalent to 9.67 milliseconds.

[0301] In step F203, an initializing position is set for scanning thereceive data accumulated in the RAM 111.

[0302] In step F204, the accumulated receive data is then scanned, and asearch made for changes (changed points) in the data. This processcontinues until a change point is found, or until determined in stepF205 that scanning of the accumulated data is complete.

[0303] The search scanning for change point data is a process forchecking the optimal sampling phase from among 8 types of samplingphases. The above described receive data RD is Manchester-coded data,and is subjected to 8-times (8×) oversampling and accumulated in the RAM111. A portion of a typical Manchester-coded data string is shown inFIG. 8B. Here, of the stored data values sampled by 8× oversampling forexample, every one Manchester-coded data of “10” or “01” shown by an ◯is eight point values (“1” or “0”). In other words, each (one) datasample is shown by eight ◯ so that 1024 bytes of Manchester-coded datareceive data becomes 8192 samples.

[0304] Here, sampling must be performed at the correct sampling phase toobtain the original data “1” and “0” from the Manchester-coded data.This is a sampling phase correctly separated from the data change point,as shown by SPP or SPN in FIG. 8B.

[0305] In the SPP or SPN sampling of FIG. 8B, when data is sampled withan SPP sampling phase, the original “1” “0” “1” data string is extractedunchanged from the 8× sampled Manchester-coded data. However, whensampled with an SPN sampling phase, a “0” “1” “0” data string isextracted, however this is eventually restored to the original datastring of “1” “0” “1” by inverting each data.

[0306] The data scanning of step F204 is a process for distinguishingoptimal phase SPP or SPN.

[0307] When data scanning in sequence time-wise starting from pastsignals for example, a change in data for example may be found at thepoint shown by the arrows CP in FIG. 8B. When this kind of data changepoint is detected, the process proceeds to step F206, and the nextsampling point (=data change position+1) is set for the optimal samplingphase. In other words, the arrows SPP in FIG. 8B are the optimalsampling phase.

[0308] In FIG. 8B, SPP was selected however SPN may sometimes beselected according to the data string. Whether or not the optimalsampling phase corresponds to SPP or to SPN is determined at the synchdetection stage. This is a logic check according to the synch. Whenfound that SPN was selected, each piece of data in data sampling fromthen onwards is inverted so that the data is correctly demodulated.

[0309] When the optimal sampling phase is detected, the detection of thepreamble with the data structure shown in FIG. 7 is performed in stepF207. The preamble data is Manchester-coded data which is “0” “1” datarepeating at periodic intervals. The preamble data length, is two bytesor in other words 16 bits just as shown in FIG. 7, and after Manchesterencoding, the data is inverted 32 times.

[0310] However the data will not all be a match. This happens because inactual use, the data is lost from the beginning portion of the preambledata, until the RF section 4 b operation in FIG. 3 stabilizes. Whenscanning to attempt to match a data string whose polarity was inverted32 times, the preamble may not be detected at all or data may bedetected by mistake if data equivalent to preamble data in a user datastring is present.

[0311] Therefore, when detecting the preamble, a check is made to findif the sampled data was inverted a fixed number of times less than 32times (for example 4 times) . Using the data inversion count in this wayas a basis for detecting the preamble, takes into account the fact thatthe beginning portion of the preamble data may be lost, and also that anoptimal sampling phase has not been verified, so that a suitable number(for example 4 times) smaller than 32 times is used for reliablydetecting a candidate preamble.

[0312] If the location being scanned is an actual preamble data string,then this kind of detection allows reliably detecting the preamble.

[0313] At this stage however, whether the optimum sampling phase is SPPor SPN is not determined.

[0314] Preamble detection is carried out in this way however if thepreamble cannot be correctly detected, then an optimal sampling phasehas not been set so the process returns in a loop of steps F204, F205.

[0315] When the preamble is detected, then the data that should bearranged behind the preamble is detected in step F208. A logic check ismade simultaneously as to whether the optimum sampling phase is SPP oris SPN. If the synch was not detected here, then the optimal samplingphase that was set is not correct, so the process returns in a loop ofsteps F204, F205.

[0316] When detecting the synch, a synch data string having positive ornegative logic is prepared beforehand, and a scanning search made tofind if either of the data strings is a match. If the positive synchdata string is a match, then the optimal sampling phase is determined instep F206 to correspond to SPP. If negative logic, then it correspondsto SPN. If neither (data string) is a match, then the synch could not bedetected.

[0317] In the explanation for FIG. 8B, assuming that the synch data is athree bit positive logic synch data string of “1” “0” “1”, then thenegative logic data string becomes “0” “1” “0”. A check is made for amatch with either string, and the logic that matches, reveals whetherthe sampling phase is SPP or is SPN. The correct sampling phase can bedetermined and the logic also confirmed.

[0318] By detecting the preamble and the synch while provisionallysetting the sampling phase in this way, in the process of steps F204through F208, whether or not the sampling phase is ideal and correctlyset can be determined, and the logic can be confirmed at the same time.

[0319] When determined that an ideal sampling phase was still not foundand the accumulated data is terminated (scan-search of all accumulateddata has ended) in step F205, then nothing could be received and theprocess terminates as an error in step F213.

[0320] When the preamble and synch were correctly detected for thesampling phase set in step F206, then in step F209, the sampling phaseset at that point is determined to be the correct and ideal samplingphase. The logic is also confirmed at the same time. In the sample fromhere onwards, the data is inverted if negative logic, in order to obtainthe correct data.

[0321] Then, the process proceeds to step F210, and a packet datalength, that is, the value of length in data structure in FIG. 7 issampled to determine the data length.

[0322] Then in step F211, the packet data for the determined data lengthportion is sampled.

[0323] Namely, the accumulated data in the above optimal sampling phaseis extracted in order to extract the data and CRC shown in FIG. 7. Thedata contents are command codes showing read-out data andacknowledgments.

[0324] A CRC check is made of the extracted data in step F212. If thecheck results are not OK, then the process proceeds to step F214 andterminates abnormally as a CRC error.

[0325] When the CRC check is OK, the normal receive was achieved and thereceive process ends in step F215. This receive data of course is sentto the library controller 80.

[0326] In the above embodiment, encoding and decoding were implementedon the CPU 110 by software processing, for sending and receiving per theremote memory interface 32. A dedicated (custom) IC is therefore notrequired for encoding and decoding. Since in particular, the CPU 110 aspreviously described is a general-purpose microcomputer, a compact shapeand low cost can also be achieved. Further, even in cases where thecommunication method has been changed, the present invention can stillbe used by simply modifying the software.

[0327] Also in the above embodiment, the operating clock frequency ofthe CPU 110 matched the carrier frequency of 13.56 MHz (or a frequencycorresponding to at least n times the carrier). Further, these are incomplete synchronization, since the operating clock for the CPU 110 andthe carrier are generated from a clock pulse from one clock generator130.

[0328] A perfectly correct rate (106 Kbps) can therefore be obtainedduring transmit just by setting the frequency division rate on theserial port 112 as needed.

[0329] Synchronization during receive is generally the largest problemin a normal communications system, however in the remote memory chip 4of this embodiment, the carrier operates (and is sent back) on astandard clock so the receive data sampling speed (8 times 106 Kbps) canalso be set to obtain a perfectly correct speed for that frequency, justby setting the serial port 112 to the correct frequency division.

[0330] Synchronization of the receive data in the remote memoryinterface 32 is therefore almost completely unnecessary, so thatsynchronization control by using a PLL circuit for example isunnecessary. The provision “almost” is inserted before “completelyunnecessary” because processing to detect the optimal sampling phase orin other words, only repeat synchronization is required. An overall lookreveals that synchronization is greatly simplified compared to ordinarycommunication systems.

[0331] In the case of the above embodiment, receive data is decoded byprocessing in the RAM 111 and a so-called batch demodulation andtherefore different from decoding systems that demodulate in succession(one after another) on dedicated (custom) ICs of the conventional art.

[0332] This batch demodulation not only increases flexibility such asfor decode timing and processing procedures but also allows processingsuch as indexing (searching) past receive data, etc.

[0333] Encode processing is also the same in that process flexibility isexpanded by utilizing the RAM 111 to form transmit data.

[0334] The example in the above embodiment described a remote memoryinterface 32 for the library device 50 as the communication device ofthe present invention, needless to say however, the remote memoryinterface 30 for the tape streamer drive 10 is also applicable in thesame way to the present invention.

[0335] The above embodiment also described using software to processphysical layers of communication (data demodulation and modulation) withthe CPU 110, however the processing may also be performed on a higherlayer on the same CPU. The library controller 80 for example, outputs aninstruction to the CPU 110 to read out a serial number from among thecontents on the remote memory chip 4. The CPU 110 receives thatinstruction and interprets and dismantles the address range within theapplicable memory. The previously mentioned layers of physicalprocessing are performed and data within the applicable range is readout (Readout may be performed multiple times according to the contents,and parity checks also made.), summarized into a form requested by thelibrary controller 80 and reported.

[0336] The embodiment of the present invention was described above,however the present invention is not limited by the structures andoperation shown in the figures explained up to here and the compositionof the library device and tap streamer drive, the composition of theremote memory interface, the communication method with the remote memorychip, and the procedures for the transmit process/receive process can bechanged as needed according to conditions of actual use. The nonvolatilememory within the remote memory chip is of course not limited to andEEP-ROM.

[0337] The embodiment of the present invention described a communicationdevice (remote memory interface) installed in a tape streamer drive andlibrary device for tape cassettes equipped with a nonvolatile memory forrecording and playback of digital signals, however the present inventionis not limited to this and may for example also be applied torecord/playback systems capable of recording and playback of videosignal and audio information.

What is claimed is:
 1. A communications device for a non-contact type semiconductor memory, which sends and receives data to a non-contact type semiconductor memory containing a memory section installed in a recording medium for storing information relating to said recording medium, and a communications section for non-contact data transfer to said memory section, comprising: send/receive means for sending and receiving communications without direct physical contact; data processing means for encoding transmit data and decoding received data, wherein: along with said data processing means performing said encoding and decoding by software processing utilizing a memory section connected to a microcomputer or formed inside said microcomputer, a clock operating frequency matches the carrier frequency of the send/receive signal of said send/receive means.
 2. A communications device for a non-contact type semiconductor memory according to claim 1, comprising one clock generating means, wherein an operation clock of said data processing means and a carrier of the send/receive signal are generated based on the clock frequency from said clock generating means.
 3. A communications device for a non-contact type semiconductor memory according to claim 1, wherein said data processing means accumulates the receive data obtained by said send/receive means in said memory section at specified periods, and decodes the received data accumulated in said memory section.
 4. A communications device for a non-contact type semiconductor memory according to claim 1, wherein said data processing means encodes the data strings of transmit data forming said data in said memory section, and data streams of said transmit data are supplied to said send/receive means and transmitted. 